Are Borders Obsolete?

Tim De Chant considers state lines:

Obvious examples of their obsolescence abound: The New York metropolitan area has grown to encompass counties in four states. Kansas City is really two different municipalities divided by the Missouri-Kansas border. Chicago's Metra commuter rail stretches into neighboring Wisconsin, just as Washington, D.C.'s Metro trains and buses collect riders from Maryland and Virginia.

He cites a recent study examining which borders actually matter. Researchers used bill tracking data from the website Where's George:

Though there are 48 states, the researchers found evidence of only about 12 distinct regions. The Midwest remained largely in tact, as does New England. But Pennsylvania was split in two by the Appalachian Mountains, while the southern half of Georgia was given over to Florida (which in turn lost part of its panhandle to a new Gulf shores region). And as far as Where’s George data is concerned, most of the western United States is indistinguishable.